Heat pipe with temperature control

ABSTRACT

Methods and apparatus for controlling the boiling temperature of a fluid within a heat pipe are disclosed. According to one aspect of the present invention, a method for controlling a temperature associated with a heat pipe that contains a fluid and has an evaporator end includes measuring the temperature associated with the heat pipe and determining when the temperature associated with the heat pipe is at a desired level. The method also includes changing a pressure within the heat pipe when it is determined that the temperature associated with the heat pipe is not at a desired level. Changing the pressure within the heat pipe causes the temperature associated with the heat pipe to change.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates generally to semiconductorprocessing equipment. More particularly, the present invention relatesto a heat pipe with an internal temperature that may be readilycontrolled by changing the pressure within the heat pipe.

[0003] 2. Description of the Related Art

[0004] For precision instruments such as photolithography machines whichare used in semiconductor processing, factors which affect theperformance, e.g., accuracy, of the precision instrument generally mustbe dealt with and, insofar as possible, eliminated. When the performanceof a precision instrument is adversely affected, as for example bydisturbance forces or by excessive heat, products formed using theprecision instrument may be improperly formed and, hence, defective. Forinstance, a photolithography machine which is subjected to disturbanceforces may cause an image projected by the photolithography machine tomove, and, as a result, be aligned incorrectly on a projection surfacesuch as a semiconductor wafer surface.

[0005] Scanning stages such as wafer scanning stages and reticlescanning stages are often used in semiconductor fabrication processes,and may be included in various photolithography and exposureapparatuses. Wafer scanning stages are generally used to position asemiconductor wafer such that portions of the wafer may be exposed asappropriate for masking or etching. Reticle scanning stages aregenerally used to accurately position a reticle or reticles for exposureover the semiconductor wafer. Patterns are generally resident on areticle, which effectively serves as a mask or a negative for a wafer.When a reticle is positioned over a wafer as desired, a beam of light ora relatively broad beam of electrons may be collimated through areduction lens, and provided to the reticle on which a thin metalpattern is placed. Portions of a light beam, for example, may beabsorbed by the reticle while other portions pass through the reticleand are focused onto the wafer.

[0006] A stage such as a wafer scanning stage or a reticle scanningstage is typically supported by a base structure such that the stage maymove in a linear direction. The base structure often includes or housesvarious sensors and actuators which serve to control the motion of thestage and a table, e.g., a wafer table, which is a part of an overallstage apparatus. Such actuators are often arranged to control a coarsestage of an overall wafer stage, and include coils which generate heat.The heat generated by the coils may be relatively significant, e.g.,significant enough to affect an exposure process performed using theoverall wafer stage. The heat generated may be, for example, in therange of approximately 10 degrees Celsius to approximately 20 degreesCelsius higher than a desired ambient temperature. Since the heatgenerated by the coils may adversely affect the performance of theoverall wafer stage by, for example, interfering with the operation ofsensors such as interferometers, the generated heat is generally carriedaway or otherwise removed from the vicinity of relatively criticalcomponents of the overall wafer stage. Carrying heat away fromrelatively critical components, as for example a wafer, reduces theeffect of excessive heat on the critical components.

[0007] One device that may be used to carry heat away from relativelycritical components is a heat pipe. For example, a heat source such as alinear motor within a stage device may be substantially in contact witha heat pipe which is arranged to remove heat from the heat source and totransfer the heat to a heat sink. FIG. 1 is a diagrammaticrepresentation of a conventional heat pipe. A heat pipe 100 includes anevaporator end 102 and a condenser end 104. Heat pipe 100 may generallybe configured as a hollow cylindrical tube that is substantially linedwith wicking material 112, e.g., a cotton sleeve. When heat is generatedby a heat source 106, a fluid in liquid form that is contained withinheat pipe 100 may be heated to its boiling point by heat source 106 atevaporator end 102. The fluid is typically a fluid which takes on agaseous or vapor state when heated, and a liquid state when cooled. Whenheated at evaporator end 102, the fluid may be conducted towards a heatsink 107 positioned near condenser end 104, as indicated by arrows 108.It should be understood that heat sink 107 may be the environment aroundheat pipe 100, and may not necessarily be a physical component.

[0008] Heat sink 107 is arranged to remove the heat from the fluid and,as a result, allows the fluid to be cooled. That is, fluid at condenserend 104 condenses and transfers its latent heat of vaporization to heatsink 107. Cooled fluid may be returned through heat pipe 100 to heatsource 102 when the condensed fluid enters wicking material 112 which islocated within heat pipe 100. Capillary action then forces the condensedfluid through wicking material 112 back to evaporator end 102, asindicated by arrows 110.

[0009] In some cases, the ability to control the boiling temperature offluid within a heat pipe may be needed such that the temperature of aheat source such as heat source 106 of FIG. 1 may be controlled.Controlling the temperature of a heat source may be critical, as manysystems may require that the temperature of a heat source, e.g., thesurface temperature of a coil of a linear motor, be maintained as closeto an ambient temperature such as room temperature as possible. Tocontrol the temperature of a heat source, the boiling temperatureassociated with a fluid contained within a heat pipe may be controlled.For example, a heat pipe may be “charged” to alter the boilingtemperature of fluid contained within the heat pipe to lower it to alevel which enables the surface temperature of a coil of a linear motorto be maintained at a desired level. Charging a heat pipe generallyincludes adding a fluid such as water inside a heat pipe, or removing afluid from a heat pipe, to alter the boiling temperature of the heatpipe. As shown in FIG. 2, additional fluid 230 may be added to anevaporator end 202 of a heat pipe 200 when it is desired for the boilingtemperature associated with heat pipe 200 to be altered. Although aprocess of charging heat pipe 200 may be effective in altering theboiling temperature associated with heat pipe 200 and, hence thetemperature associated with evaporator end 202, it is generallydifficult to charge heat pipe 200 except at one time during themanufacturing process. Thus, the boiling temperature remains effectivelyconstant during the use of heat pipe 200.

[0010] Some heat pipes have been designed to enable temperaturesassociated with the heat pipes to be substantially controlled, even ifboiling temperatures associated with the heat pipes are essentially notcontrolled. A gas-loaded, variable conductance heat pipe, for example,may be used in some cases to enable the temperature within a heat pipeto remain fairly constant. Allowing the temperature within a heat pipeto remain fairly constant may allow a heat pipe to operate moreefficiently, although the temperature at an evaporator end of such aheat pipe is generally not changeable. FIGS. 3a and 3 b are diagrammaticrepresentations of a gas-loaded, variable conductance heat pipe. A heatpipe 300, which has an evaporator end 302 and a condenser end 304,includes a gas reservoir 340 at condenser end 304. Gas contained withinreservoir 340 has a gas front 342 which moves depending upon thetemperature of vapor contained within heat pipe 300. As gas front 342moves, the surface area of condenser end 304 varies. For instance, asshown in FIG. 3b, when gas front 342 moves into condenser end 304, thesurface area of condenser end 304 is decreased from the surface area ofcondenser end 304 as shown in FIG. 3a.

[0011] Since the surface area of condenser end 304 varies as gas front342 moves, the thermal conductance of heat pipe 300 also varies as afunction of the position of gas front 342. When the surface area ofcondenser end 304 increases, thermal conductance increases, and when thesurface area of condenser end 304 decreases, thermal conductancedecreases. As a result, a temperature drop across evaporator end 302 andcondenser end 304 is effectively controllable by moving gas front 342.While the temperature drop within heat pipe 300 may be controlled suchthat the temperature within heat pipe 300 may be maintained at asubstantially constant temperature, the use of heat pipe 300 generallydoes not enable the temperature at evaporator end 302 to be controlled.

[0012] While the use of a heat pipe to transfer heat away from criticalcomponents of an overall wafer stage system is typically effective, heatpipes generally are not able to be used to readily and efficiently allowthe temperatures of heat sources to be controlled. As discussed above,although charging a heat pipe may enable a desired boiling temperatureto be obtained within the heat pipe, it is typically difficult to chargeheat pipes except at one time during a manufacturing process. Hence, theboiling temperature within a heat pipe generally remains substantiallyconstant during the use of the heat pipe. As a result, the boilingtemperature achieved within a heat pipe may not be sufficient tomaintain a surface of a heat source at a desired temperature, since theboiling temperature of the fluid in the heat pipe effectively determinesthe constant temperature at which the evaporator end of the heat pipewhich typically contacts the heat source may be held.

[0013] Therefore, what is needed is a method and an apparatus forenabling the temperature at which fluid in a heat pipe boils to becontrolled. More specifically, what is desired is a method and anapparatus for controlling the temperature of an evaporator end of a heatpipe such that the temperature of a heat source may effectively becontrolled.

SUMMARY OF THE INVENTION

[0014] The present invention relates to a heat pipe within which theboiling temperature of a fluid may be adjusted. According to one aspectof the present invention, a method for controlling a temperatureassociated with a heat pipe that contains a fluid and has an evaporatorend includes measuring the temperature associated with the heat pipe anddetermining when the temperature associated with the heat pipe is at adesired level. The method also includes changing a pressure within theheat pipe when it is determined that the temperature associated with theheat pipe is not at a desired level. Changing the pressure within theheat pipe causes the temperature associated with the heat pipe tochange.

[0015] In one embodiment, the heat pipe includes a pressure controlmechanism, and changing the pressure within the heat pipe includesoperating the pressure control mechanism. In such an embodiment, thepressure control mechanism may include a piston assembly, and changingthe pressure within the heat pipe may include applying a controlledpressure using the piston assembly.

[0016] Controlling the temperature within a heat pipe effectively allowsthe temperature at which heat is removed from a heat source that iscooled by the heat pipe to be controlled. Specifically, the temperatureof the fluid may be controlled by substantially controlling the pressurewithin the heat pipe. When the boiling temperature of the fluid withinthe heat pipe is controlled, the temperature of the evaporator end ofthe heat pipe is essentially controlled. Hence, the temperature at whichheat is removed from a heat source, e.g., a coil of a linear motor, maybe substantially controlled by adjusting the pressure within the heatpipe. Controlling the temperature at which heat is removed from the heatsource enables the surface temperature of the heat source to be morereadily maintained at a constant level, which enhances the performanceof an overall system, e.g., a stage apparatus, which includes the heatsource.

[0017] According to another aspect of the present invention, a heat pipeincludes an evaporator end, a fluid, and a pressure control mechanism.The pressure control mechanism is arranged to change a pressure withinthe heat pipe such that a boiling temperature of the fluid is changed.In one embodiment, the pressure control mechanism is arranged to changethe pressure by increasing the pressure such that the boilingtemperature of the fluid is increased. In another embodiment, thepressure control mechanism includes a piston arrangement that applies acontrol pressure to change the pressure within the heat pipe.

[0018] According to yet another aspect of the present invention, amethod for controlling a temperature of an actuator within a stageapparatus that is in communication with an evaporator end of a heat pipeincludes determining a desired temperature for the actuator, determininga corresponding desired temperature for the evaporator end using thedesired temperature for the actuator, and adjusting a mechanism withinthe heat pipe to achieve the desired temperature for the evaporator end.Adjusting the pressure causes a boiling temperature of a fluid withinthe heat pipe to be adjusted such that a temperature of the evaporatorend is adjusted.

[0019] In one embodiment, adjusting the pressure within the heat pipeincludes applying a control force of a first amount to a pistonarrangement of the heat pipe. The control force of the first amount isarranged to cause the piston arrangement to change the pressure withinthe heat pipe. In such an embodiment, the method may also includedetermining when the temperature of the evaporator end is the desiredtemperature for the evaporator end. When the temperature of theevaporator end is the desired temperature for the evaporator end, thecontrol force is maintained at the first amount. Alternatively, when thetemperature of the evaporator end is not the desired temperature for theevaporator end, the pressure within the heat pipe may be adjusted toachieve the desired temperature for the evaporator end by applying acontrol force of a second amount to the piston arrangement.

[0020] These and other advantages of the present invention will becomeapparent upon reading the following detailed descriptions and studyingthe various figures of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention may best be understood by reference to thefollowing description taken in conjunction with the accompanyingdrawings in which:

[0022]FIG. 1 is a diagrammatic representation of a conventional heatpipe.

[0023]FIG. 2 is a diagrammatic representation of a conventional heatpipe which is chargeable. FIG. 3a is a diagrammatic representation of agas-loaded, variable conductance heat pipe.

[0024]FIG. 3b is a diagrammatic representation of a gas-loaded, variableconductance heat pipe, e.g., heat pipe 300 of FIG. 3a, with gas from areservoir present in a condenser section.

[0025]FIG. 4 is a diagrammatic representation of a heat pipe withinwhich pressure may be controlled in accordance with an embodiment of thepresent invention.

[0026]FIG. 5 is a diagrammatic representation of a heat pipe withinwhich pressure may be controlled using a piston arrangement inaccordance with an embodiment of the present invention.

[0027]FIG. 6 is a block diagram representation of actions which occurwhen a piston of a heat pipe assembly is moved in accordance with anembodiment of the present invention.

[0028]FIG. 7 is a diagrammatic representation of a heat pipe with apiston which serves as a pressure controller and an internal temperaturesensor in accordance with an embodiment of the present invention.

[0029]FIG. 8 is a diagrammatic representation of a control loop whichmay be used to control the temperature within a heat pipe in accordancewith an embodiment of the present invention.

[0030]FIG. 9 is a process flow diagram which illustrates one method ofcontrolling the temperature in a heat pipe by adjusting the pressure inthe heat pipe in accordance with an embodiment of the present invention.

[0031]FIG. 10a is a diagrammatic representation of a piston which isactuated by a voice coil motor in accordance with an embodiment of thepresent invention.

[0032]FIG. 10b is a diagrammatic representation of a piston which isactuated by an air bellows in accordance with an embodiment of thepresent invention.

[0033]FIG. 11 is a diagrammatic representation of a photolithographyapparatus in accordance with an embodiment of the present invention.

[0034]FIG. 12 is a process flow diagram which illustrates the stepsassociated with fabricating a semiconductor device in accordance with anembodiment of the present invention. FIG. 13 is a process flow diagramwhich illustrates the steps associated with processing a wafer, i.e.,step 1304 of FIG. 12, in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] When the ambient temperature around an overall precision stagedevice, e.g., an overall wafer stage device, is raised during a waferexposure process, the performance of the stage device may becompromised. As a result, errors or inconsistencies may arise during awafer exposure process that is performed using the stage device when theambient temperature is raised, as for example from a desired temperaturein the range of approximately 20 to approximately 25 degrees Celsius toa temperature in the range of approximately 30 to approximately 40degrees Celsius. Often, heat which is generated by actuators associatedwith a stage device causes the ambient temperature to be raised. Inorder to reduce the amount by which the ambient temperature is raised byactuators such as linear motors or motors with electromagnetic coils,heat pipes may be used to carry heat away from the actuators to heatsinks that absorb the heat.

[0036] Typically, heat pipes are used to enable the surface temperatureof a coil, e.g., a coil of a linear motor, to be maintained at aparticular temperature such as room temperature. Although a heat pipe isgenerally effective in carrying heat away from the coil, when thetemperature at which a heat pipe operates to transfer heat away from thecoil is too high, the coil may not be cooled sufficiently, andconvection in the air surrounding the coil may cause the air to beheated up and, hence, interfere with the measurements made by sensorssuch as interferometers.

[0037] By controlling the temperature of a heat transfer medium, e.g., afluid, within a heat pipe, the temperature at which heat is removed froma heat source such as an actuator may be controlled. In one embodiment,the temperature of the heat transfer medium, particularly at anevaporator end of a heat pipe, may be controlled by substantiallycontrolling the pressure within the heat pipe. Controlling the pressurewithin the heat pipe enables the boiling temperature of fluid within theheat pipe to be controlled, which effectively enables the temperature ofthe evaporator end of the heat pipe to be controlled. As a result, thetemperature at which heat is removed from a heat source, e.g., a coil ofa linear motor, may be substantially controlled by adjusting thepressure within the heat pipe. Controlling the temperature at which heatis removed from the heat source enables the surface temperature of theheat source to be more readily maintained at a constant level.

[0038]FIG. 4 is a diagrammatic representation of a heat pipe withinwhich pressure may be controlled in accordance with an embodiment of thepresent invention. A heat pipe 404 may be arranged between a heat source416, e.g., heat generating coils of an actuator, and a heat sink 420,e.g., the environment surrounding heat pipe 404. Specifically, heatsource 416 is positioned at an evaporator end 408 of heat pipe 404,while heat sink 420 is positioned at a condenser end 412 of heat pipe404. A pressure control mechanism 424, which is effectively a part ofheat pipe 404, is arranged to enable the pressure within heat pipe 404to be varied. Pressure control mechanism 424 may generally be positionedsubstantially anywhere with respect to heat pipe 404. In one embodiment,pressure control mechanism 424 may be a piston which is subjected to acontrol force, as will be described below with respect to FIG. 5. Itshould be appreciated, however, that pressure control mechanism 424 maygenerally be substantially any mechanism which enables the pressurewithin heat pipe 404 to be varied.

[0039] Typically, by increasing the pressure within heat pipe 404, theboiling temperature of a fluid which is either in a liquid state or agas-liquid state may be increased. On the other hand, by decreasing thepressure within heat pipe 404, the boiling temperature of the fluidwhich is either in a liquid state or a gas-liquid state may be lowered.When the boiling point or temperature of the fluid within heat pipe 404changes, then the temperature at evaporator end 408, which generallycontains the fluid in a liquid state, changes. As such, changing theboiling temperature of the fluid changes the temperature of evaporatorend 408 and, hence, the temperature at which heat source 416 may bemaintained may effectively be changed, since heat source 416 isgenerally in communication with evaporator end 408. By way of example,when the pressure within heat pipe 404 increases and the boilingtemperature of the fluid within heat pipe 404 5 increases, then heatgenerated by heat source 416 may be substantially dissipated by heatpipe 404 at a higher temperature. Hence, allowing the boilingtemperature of fluid within heat pipe 404 to be substantially controlledusing pressure control mechanism 424 allows the temperature associatedwith evaporator end 408 and the temperature of heat source 416 to becontrolled.

[0040] As mentioned above, one suitable pressure control mechanism 424is a piston mechanism. Referring next to FIG. 5, one embodiment of aheat pipe within which pressure may be controlled using a piston will bedescribed in accordance with an embodiment of the present invention. Aheat pipe 504 which includes an evaporator end 508 and a condenser end512 is positioned between a heat source 516 and a heat sink 520 suchthat heat source 516 is located at evaporator end 508 and heat sink 520is located at condenser end 512. A piston 514 is positioned with respectto heat pipe 504 such that when a control force 530, which may beapplied through an actuator that is controlled by a control mechanism,is applied to piston 514, piston 514 may cause a pressure within heatpipe 504, i.e., an internal pressure of heat pipe 504, to change. Piston514 may cause the pressure within heat pipe 504 to change by effectivelyapplying a control pressure within heat pipe 504. In order to preventfluid from escaping from heat pipe 504, a diaphragm (not shown) may beused in one embodiment to effectively create a seal that prevents fluidfrom leaking out from heat pipe 504 through any gaps which are presentbetween piston 514 and heat pipe 504. It should be appreciated thatapplying a control pressure within heat pipe 504 may also cause at leasta slight volume change within heat pipe 504.

[0041] Piston 514 generally has an associated surface area whicheffectively comes into contact with an interior of heat pipe 504. Assuch, the control pressure applied by piston 514 may be expressed as afunction of control force 530 and the contact area of piston 514. Hence,by increasing control force 530, the control pressure applied by piston514 may be increased, and the pressure within heat pipe 504 may rise.Generally, when control force 530 is applied in a negative y-direction540, piston 514 moves in negative y-direction 540 and causes thepressure within heat pipe 504 to increase. Alternatively, when controlforce 530 is applied in a positive y-direction 540, piston moves inpositive y-direction 540 and typically causes the pressure within heatpipe 504 to decrease.

[0042] With reference to FIG. 6, the actions which occur when a pistonof a heat pipe assembly is moved will be discussed in accordance with anembodiment of the present invention. When the force applied to a pistonof a heat pipe, e.g., piston 514 of FIG. 5, is adjusted in action 610,the pressure within the heat pipe changes in action 614. By way ofexample, when the force applied to the piston is increased, the pressurewithin the heat pipe may increase. A change in pressure within the heatpipe causes the boiling temperature of the fluid in the heat pipe tochange in action 618. At a given pressure, when the fluid in the heatpipe is in a gas-liquid state, changing the pressure within the heatpipe changes the boiling temperature of the fluid, as will beappreciated by those skilled in the art. For an embodiment in which thepressure within the heat pipe is increased, the boiling temperature ofthe fluid in the heat pipe typically increases.

[0043] Once the boiling temperature of the fluid in the heat pipechanges, the temperature at the evaporator end of the heat pipe changesin action 622. Since the evaporator end of the heat pipe is generally inthe vicinity of a heat source, by changing the temperature at theevaporator end of the heat pipe, the temperature at which heat isremoved from the heat source is also changed.

[0044] To monitor the temperature of the fluid in the heat pipe or, moreparticularly, the evaporator end of a heat pipe, in order to ascertainwhether the boiling temperature of fluid within the heat pipe is at adesired level or needs to be changed to reach the desired level, atemperature sensor may be positioned within the heat pipe. FIG. 7 is adiagrammatic representation of a heat pipe with a piston which serves asa pressure controller and an internal temperature sensor in accordancewith an embodiment of the present invention. A heat pipe 602 includes apiston 614 which is controlled by a force 618. To determine anappropriate amount of force 618 to apply to piston 614 to achieve adesired boiling temperature within heat pipe 602, a temperature sensor640 may be positioned at an evaporator end 606 of heat pipe 602.Temperature sensor 640 may generally be used to measure a temperature offluid within heat pipe 602, and may be substantially any suitabletemperature sensor 640. Suitable temperature sensors or transducers mayinclude, but are not limited to, thermometers such as thermocouplethermometers, and thermistor thermometers, as well as thermoelectricsensors and resistive temperature sensors.

[0045] Output from temperature sensor 640 may be provided to acontroller which provides force 618 such that the magnitude of force 618may be adjusted as appropriate to create a pressure within heat pipe 602which is suitable for causing a temperature within heat pipe 602 to beraised or lowered. As shown in FIG. 8, which is a diagrammatic blockdiagram representation of one suitable control loop which may be used tocontrol the temperature within a heat pipe such as heat pipe 602, adesired temperature 802 for an evaporator end of a heat pipe is providedas a control input in a control loop 800. The desired temperature 802 isprovided to a controller 806, e.g., by a user who specifies desiredparameters of the heat pipe, which controls an actuator 808 thatprovides a control force to a piston of the heat pipe. In oneembodiment, actuator 808 may be a voice coil motor, a linear motor, orsubstantially any electromagnetic actuator.

[0046] A measured temperature 810, which may be provided by atemperature sensor within the heat pipe, is also provided as an input tocontroller 806. Using desired temperature 802 and measured temperature810, controller 806 may determine an appropriate amount, or level, offorce to be exerted by actuator 808 on a piston of the heat pipe toenable measured temperature 810 to be approximately the same as desiredtemperature 802. It should be appreciated that controller 806 maysubstantially continuously adjust actuator 808 as necessary and, hence,the pressure within the heat pipe, as needed to effectively maintainmeasured temperature 810 at a level that is approximately the same asdesired temperature 802.

[0047] Referring next to FIG. 9, one method of controlling thetemperature in a heat pipe by adjusting the pressure in the heat pipewill be described in accordance with an embodiment of the presentinvention. A process 900 of controlling the temperature in a heat pipebegins at step 902 in which a determination is made regarding what thedesired temperature for the evaporator end of the heat pipe is.Determining what the desired temperature is may include obtaining adesired temperature from a user of the heat pipe, or determining adesired temperature based upon the requirements of an overall stageapparatus which uses the heat pipe. For example, a desired surfacetemperature for an actuator which is being cooled using the heat pipemay be used to determine a corresponding desired temperature for theevaporator end of the heat pipe. It should be appreciated that althoughthe desired temperature for the evaporator end of the heat pipe may bethe same as the desired temperature for the actuator, the two desiredtemperatures may also vary.

[0048] After the desired temperature is determined, the temperature atan evaporator end of the heat pipe may be measured in step 906. Althoughthe temperature is typically measured within the heat pipe at anevaporator end to enable a desired temperature to be maintained at theevaporator end, it should be appreciated that the temperature within theheat pipe may be measured substantially anywhere within the heat pipe.Alternatively, the temperature of the actuator, some other temperature,or a performance parameter related to the temperature of the actuator,e.g., air turbulence or sensor noise, may be measured. Once thetemperature within the heat pipe is measured, it is determined in step908 whether the temperature at the evaporator end of the heat pipe is asdesired. If it is determined that the temperature at the evaporator endof the heat pipe is as desired, then the indication is that the pressurewithin the heat pipe is sufficient for maintaining the boiling point ofliquid within the heat pipe at a desired temperature. Accordingly, instep 912, the current control force applied to the piston of the heatpipe is maintained at it current level. That is, the actuator whichcauses the control force to be applied to the piston effectively doesnot change the amount of control force that is applied to the piston.From step 912, process flow returns to step 906 in which the temperatureat the evaporator end of the heat pipe is measured.

[0049] Returning to step 908, if it is determined that the temperatureat the evaporator end of the heat pipe is not as desired, then theimplication may be that the pressure within the heat pipe is either toohigh or too low for the desired temperature to be achieved. For example,if the temperature at the evaporator end of the heat pipe is too high,then the pressure in the heat pipe is likely to be too high to enablethe desired temperature at the evaporator end to be achieved. As such,from step 908, process flow moves to step 910 in which the control forceapplied to the piston of the heat pipe, e.g., using an actuator, isadjusted to adjust the pressure within the heat pipe. Typically, theadjustment made to the control force is arranged to be sufficient toalter the pressure within the heat by an amount that is sufficient toachieve the desired temperature at the evaporator end of the heat pipe.Once the control force is adjusted, process flow returns to step 906 inwhich the temperature at the evaporator end of the heat pipe ismeasured.

[0050] In general, an actuator used to vary the force applied to apiston of a heat pipe may be substantially any suitable actuator thatmay be controlled, as for example by a controller which sends signals tothe actuator to alter the force generated by the actuator. By way ofexample, an actuator which is coupled to the piston of the heat pipe maybe a motor such as a voice coil motor (VCM). FIG. 10a is a diagrammaticrepresentation of a piston which is actuated by a VCM in accordance withan embodiment of the present invention. A heat pipe 950 includes apiston 944 which is coupled to a VCM 930. As shown, a body 934 of VCM930 is coupled to piston 944 such that magnets 936 in cooperation with acoil 932 cause body 934 to move and create a force on piston 944. Often,forces on piston 944 created by VCM 930 may either cause piston 944 tobe moved in a positive y-direction 948, or in a negative y-direction948. A diaphragm 940 or similar mechanism may be arranged to preventfluid contained in an interior 954 of heat pipe 950 from leaking aroundpiston 944 and out of heat pipe 950. As piston 944 moves, the pressurewithin interior 954 may change as a function of the force applied by VCM930 on piston 944 and the area of piston 944.

[0051] Another actuator which may be used to apply force to a piston ofa heat pipe is an air bellows. FIG. 10b is a diagrammatic representationof a piston which is actuated by an air bellows in accordance with anembodiment of the present invention. A heat pipe 980 includes a piston974 which may be sealed using a diaphragm 970 to prevent leakage offluid contained in an interior 984 of heat pipe 980. Piston 974 may becoupled to an air bellows 960 which may be used to alter a control forceapplied to piston 974 and, hence, the pressure within interior 984.Typically, the amount of force applied by air bellows 960 onto piston974 may be varied by altering the air pressure within bellows 960. As aresult, movement of piston 974 in a y-direction 968 may be controlled bycontrolling the air pressure within bellows 960.

[0052] A heat pipe with a controllable internal temperature maygenerally be incorporated as part of an apparatus such as aphotolithography apparatus. By way of example, a heat pipe withtemperature control may be applied to a coil of an electromagneticactuator in a photolithography apparatus, or a heat pipe withtemperature control may be connected to a linear motor within thephotolithography apparatus. With reference to FIG. 11, aphotolithography apparatus which may include a heat pipe withtemperature control will be described in accordance with an embodimentof the present invention. A photolithography apparatus (exposureapparatus) 40 includes a wafer positioning stage 52 that may be drivenby a planar motor (not shown), as well as a wafer table 51 that ismagnetically coupled to wafer positioning stage 52 by utilizing anEI-core actuator. The planar motor which drives wafer positioning stage52 generally uses an electromagnetic force generated by magnets andcorresponding armature coils arranged in two dimensions. A wafer 64 isheld in place on a wafer holder or chuck 74 which is coupled to wafertable 51. Wafer positioning stage 52 is arranged to move in multipledegrees of freedom, e.g., between three to six degrees of freedom, underthe control of a control unit 60 and a system controller 62. Themovement of wafer positioning stage 52 allows wafer 64 to be positionedat a desired position and orientation relative to a projection opticalsystem 46. Heat generated during the movement of wafer positioning stage52 may be stored by a heat pipe (not shown) that is coupled to waferpositioning stage 52.

[0053] Wafer table 51 may be levitated in a z-direction 10 b by anynumber of voice coil motors (not shown), e.g., three voice coil motors.In the described embodiment, at least three magnetic bearings (notshown) couple and move wafer table 51 along a y-axis 10 a. The motorarray of wafer positioning stage 52 is typically supported by a base 70.Base 70 is supported to a ground via isolators 54. Reaction forcesgenerated by motion of wafer stage 52 may be mechanically released to aground surface through a frame 66. One suitable frame 66 is described inJP Hei 8-166475 and U.S. Pat. No. 5,528,118, which are each hereinincorporated by reference in their entireties.

[0054] An illumination system 42 is supported by a frame 72. Frame 72 issupported to the ground via isolators 54. Illumination system 42includes an illumination source, and is arranged to project a radiantenergy, e.g., light, through a mask pattern on a reticle 68 that issupported by and scanned using a reticle stage which includes a coarsestage and a fine stage. The radiant energy is focused through projectionoptical system 46, which is supported on a projection optics frame 50and may be supported the ground through isolators 54. Suitable isolators54 include those described in JP Hei 8-330224 and U.S. Pat. No.5,874,820, which are each incorporated herein by reference in theirentireties.

[0055] A first interferometer 56 is supported on projection optics frame50, and functions to detect the position of wafer table 51.Interferometer 56 outputs information on the position of wafer table 51to system controller 62. In one embodiment, wafer table 51 has a forcedamper which reduces vibrations associated with wafer table 51 such thatinterferometer 56 may accurately detect the position of wafer table 51.A second interferometer 58 is supported on projection optical system 46,and detects the position of reticle stage 44 which supports a reticle68. Interferometer 58 also outputs position information to systemcontroller 62.

[0056] It should be appreciated that there are a number of differenttypes of photolithographic apparatuses or devices. For example,photolithography apparatus 40, or an exposure apparatus, may be used asa scanning type photolithography system which exposes the pattern fromreticle 68 onto wafer 64 with reticle 68 and wafer 64 movingsubstantially synchronously. In a scanning type lithographic device,reticle 68 is moved perpendicularly with respect to an optical axis of alens assembly (projection optical system 46) or illumination system 42by reticle stage 44. Wafer 64 is moved perpendicularly to the opticalaxis of projection optical system 46 by a wafer stage 52. Scanning ofreticle 68 and wafer 64 generally occurs while reticle 68 and wafer 64are moving substantially synchronously.

[0057] Alternatively, photolithography apparatus or exposure apparatus40 may be a step-and-repeat type photolithography system that exposesreticle 68 while reticle 68 and wafer 64 are stationary. In one step andrepeat process, wafer 64 is in a substantially constant positionrelative to reticle 68 and projection optical system 46 during theexposure of an individual field. Subsequently, between consecutiveexposure steps, wafer 64 is consecutively moved by wafer positioningstage 52 perpendicularly to the optical axis of projection opticalsystem 46 and reticle 68 for exposure. Following this process, theimages on reticle 68 may be sequentially exposed onto the fields ofwafer 64 so that the next field of semiconductor wafer 64 is broughtinto position relative to illumination system 42, reticle 68, andprojection optical system 46.

[0058] It should be understood that the use of photolithographyapparatus or exposure apparatus 40, as described above, is not limitedto being used in a photolithography system for semiconductormanufacturing. For example, photolithography apparatus 40 may be used asa part of a liquid crystal display (LCD) photolithography system thatexposes an LCD device pattern onto a rectangular glass plate or aphotolithography system for manufacturing a thin film magnetic head.

[0059] The illumination source of illumination system 42 may be g-line(436 nanometers (nm)), i-line (365 nm), a KrF excimer laser (248 nm), anArF excimer laser (193 nm), and an F₂-type laser (157 nm).Alternatively, illumination system 42 may also use charged particlebeams such as x-ray and electron beams. For instance, in the case wherean electron beam is used, thermionic emission type lanthanum hexaboride(LaB₆) or tantalum (Ta) may be used as an electron gun. Furthermore, inthe case where an electron beam is used, the structure may be such thateither a mask is used or a pattern may be directly formed on a substratewithout the use of a mask.

[0060] With respect to projection optical system 46, when farultra-violet rays such as an excimer laser is used, glass materials suchas quartz and fluorite that transmit far ultra-violet rays is preferablyused. When either an F₂-type laser or an x-ray is used, projectionoptical system 46 may be either catadioptric or refractive (a reticlemay be of a corresponding reflective type), and when an electron beam isused, electron optics may comprise electron lenses and deflectors. Aswill be appreciated by those skilled in the art, the optical path forthe electron beams is generally in a vacuum.

[0061] In addition, with an exposure device that employs vacuumultra-violet (VUV) radiation of a wavelength that is approximately 200nm or lower, use of a catadioptric type optical system may beconsidered. Examples of a catadioptric type of optical system include,but are not limited to, those described in Japan Patent ApplicationDisclosure No. 8-171054 published in the Official gazette for Laid-OpenPatent Applications and its counterpart U.S. Pat. No. 5,668,672, as wellas in Japan Patent Application Disclosure No. 10-20195 and itscounterpart U.S. Pat. No. 5,835,275, which are all incorporated hereinby reference in their entireties. In these examples, the reflectingoptical device may be a catadioptric optical system incorporating a beamsplitter and a concave mirror. Japan Patent Application Disclosure (Hei)No. 8-334695 published in the Official gazette for Laid-Open PatentApplications and its counterpart U.S. Pat. No. 5,689,377, as well asJapan Patent Application Disclosure No. 10-3039 and its counterpart U.S.Pat. No. 5,892,117, which are all incorporated herein by reference intheir entireties. These examples describe a reflecting-refracting typeof optical system that incorporates a concave mirror, but without a beamsplitter, and may also be suitable for use with the present invention.

[0062] Further, in photolithography systems, when linear motors (seeU.S. Pat. Nos. 5,623,853 or 5,528,118, which are each incorporatedherein by reference in their entireties) are used in a wafer stage or areticle stage, the linear motors may be either an air levitation typethat employs air bearings or a magnetic levitation type that usesLorentz forces or reactance forces. Additionally, the stage may alsomove along a guide, or may be a guideless type stage which uses noguide.

[0063] Alternatively, a wafer stage or a reticle stage may be driven bya planar motor which drives a stage through the use of electromagneticforces generated by a magnet unit that has magnets arranged in twodimensions and an armature coil unit that has coil in facing positionsin two dimensions. With this type of drive system, one of the magnetunit or the armature coil unit is connected to the stage, while theother is mounted on the moving plane side of the stage.

[0064] Movement of the stages as described above generates reactionforces which may affect performance of an overall photolithographysystem. Reaction forces generated by the wafer (substrate) stage motionmay be mechanically released to the floor or ground by use of a framemember as described above, as well as in U.S. Pat. No. 5,528,118 andpublished Japanese Patent Application Disclosure No. 8-166475.Additionally, reaction forces generated by the reticle (mask) stagemotion may be mechanically released to the floor (ground) by use of aframe member as described in U.S. Pat. No. 5,874,820 and publishedJapanese Patent Application Disclosure No. 8-330224, which are eachincorporated herein by reference in their entireties.

[0065] Isolaters such as isolators 54 may generally be associated withan active vibration isolation system (AVIS). An AVIS generally controlsvibrations associated with forces 112, i.e., vibrational forces, whichare experienced by a stage assembly or, more generally, by aphotolithography machine such as photolithography apparatus 40 whichincludes a stage assembly.

[0066] A photolithography system according to the above-describedembodiments, e.g., a photolithography apparatus which may include one ormore heat pipes, may be built by assembling various subsystems in such amanner that prescribed mechanical accuracy, electrical accuracy, andoptical accuracy are maintained. In order to maintain the variousaccuracies, prior to and following assembly, substantially every opticalsystem may be adjusted to achieve its optical accuracy. Similarly,substantially every mechanical system and substantially every electricalsystem may be adjusted to achieve their respective desired mechanicaland electrical accuracies. The process of assembling each subsystem intoa photolithography system includes, but is not limited to, developingmechanical interfaces, electrical circuit wiring connections, and airpressure plumbing connections between each subsystem. There is also aprocess where each subsystem is assembled prior to assembling aphotolithography system from the various subsystems. Once aphotolithography system is assembled using the various subsystems, anoverall adjustment is generally performed to ensure that substantiallyevery desired accuracy is maintained within the overall photolithographysystem. Additionally, it may be desirable to manufacture an exposuresystem in a clean room where the temperature and humidity arecontrolled.

[0067] Further, semiconductor devices may be fabricated using systemsdescribed above, as will be discussed with reference to FIG. 12. Theprocess begins at step 1301 in which the function and performancecharacteristics of a semiconductor device are designed or otherwisedetermined. Next, in step 1302, a reticle (mask) in which has a patternis designed based upon the design of the semiconductor device. It shouldbe appreciated that in a parallel step 1303, a wafer is made from asilicon material. The mask pattern designed in step 1302 is exposed ontothe wafer fabricated in step 1303 in step 1304 by a photolithographysystem. One process of exposing a mask pattern onto a wafer will bedescribed below with respect to FIG. 13. In step 1305, the semiconductordevice is assembled. The assembly of the semiconductor device generallyincludes, but is not limited to, wafer dicing processes, bondingprocesses, and packaging processes. Finally, the completed device isinspected in step 1306.

[0068]FIG. 13 is a process flow diagram which illustrates the stepsassociated with wafer processing in the case of fabricatingsemiconductor devices in accordance with an embodiment of the presentinvention. In step 1311, the surface of a wafer is oxidized. Then, instep 1312 which is a chemical vapor deposition (CVD) step, an insulationfilm may be formed on the wafer surface. Once the insulation film isformed, in step 1313, electrodes are formed on the wafer by vapordeposition. Then, ions may be implanted in the wafer using substantiallyany suitable method in step 1314. As will be appreciated by thoseskilled in the art, steps 1311-1314 are generally considered to bepreprocessing steps for wafers during wafer processing. Further, itshould be understood that selections made in each step, e.g., theconcentration of various chemicals to use in forming an insulation filmin step 1312, may be made based upon processing requirements.

[0069] At each stage of wafer processing, when preprocessing steps havebeen completed, post-processing steps may be implemented. Duringpost-processing, initially, in step 1315, photoresist is applied to awafer. Then, in step 1316, an exposure device may be used to transferthe circuit pattern of a reticle to a wafer. Transferring the circuitpattern of the reticle of the wafer generally includes scanning areticle scanning stage which may, in one embodiment, include a forcedamper to dampen vibrations.

[0070] After the circuit pattern on a reticle is transferred to a wafer,the exposed wafer is developed in step 1317. Once the exposed wafer isdeveloped, parts other than residual photoresist, e.g., the exposedmaterial surface, may be removed by etching. Finally, in step 1319, anyunnecessary photoresist that remains after etching may be removed. Aswill be appreciated by those skilled in the art, multiple circuitpatterns may be formed through the repetition of the preprocessing andpost-processing steps.

[0071] Although only a few embodiments of the present invention havebeen described, it should be understood that the present invention maybe embodied in many other specific forms without departing from thespirit or the scope of the present invention. By way of example,although a heat pipe has been described as including a pressurecontroller which is a piston, a pressure controller may be substantiallyany mechanism which enables pressure within the heat pipe to becontrolled. In other words, a pressure controller on a heat pipe may notnecessarily be a piston.

[0072] A heat pipe with an internal temperature which may be controlledby controlling the pressure within the heat pipe may be used for avariety of different application. For instance, as described above, aheat pipe with an internal temperature which is controllable may be usedwithin a photolithography apparatus to cool linear motors, voice coilmotors, or substantially any other electromagnetic actuator. It shouldbe appreciated, however, that such a heat pipe may generally be used tocool substantially any mechanism or device which would benefit frombeing cooled.

[0073] While a pressure control mechanism such as a piston has beenshown as being positioned near a condenser end of a heat pipe, apressure control mechanism may generally be positioned substantiallyanywhere with respect to the heat pipe. Positioning the pressure controlmechanism closer to a condenser end of the heat pipe, which containsmostly gas or vapors, may enable the pressure control mechanism to bemore readily actuated. However, the pressure control mechanism mayinstead be located near a middle portion of a heat pipe, or closer to anevaporator end of the heat pipe in some embodiments.

[0074] Changing the pressure within a heat pipe may, in some cases,cause an appreciable change in the interior volume of the heat pipe.Conversely, changing the interior volume of a heat pipe may lead to achange in pressure within the heat pipe. As such, it should beappreciated that the internal volume of the heat pipe may effectively bechanged, e.g., by displacing a piston of the heat pipe, to cause achange in pressure within the heat pipe that leads to a change in theboiling temperature of fluid in the heat pipe.

[0075] In general, the steps associated with the methods of the presentinvention may vary widely. Steps may be added, removed, altered, andreordered without departing from the spirit or the scope of the presentinvention. For example, a process of controlling the temperature withina heat pipe may include at least periodically determining a desiredtemperature within the heat pipe. Periodically determining a desiredtemperature within the heat pipe enables changes to requirementsassociated with an overall stage apparatus to be accounted for, as thecontrol force applied to a piston of a heat pipe may be adjusted tocompensate for any change to a desired temperature. Therefore, thepresent examples are to be considered as illustrative and notrestrictive, and the invention is not to be limited to the details givenherein, but may be modified within the scope of the appended claims.

1. A method for controlling a temperature associated with a heat pipe,the heat pipe being arranged to contain a fluid, the heat pipe having anevaporator end, the evaporator end being arranged to be in the vicinityof a heat source, the method comprising: measuring the temperatureassociated with the heat pipe; determining when the temperatureassociated with the heat pipe is at a desired level; and changing apressure within the heat pipe when it is determined that the temperatureassociated with the heat pipe is not at a desired level, whereinchanging the pressure within the heat pipe changes a boiling temperatureof the fluid and causes the temperature associated with the heat pipe tochange.
 2. The method of claim 1 wherein changing the pressure withinthe heat pipe includes increasing the pressure within the heat pipe tocause the temperature associated with the heat pipe to be raised.
 3. Themethod of claim 1 wherein the heat pipe includes a pressure controlmechanism, and changing the pressure within the heat pipe includesoperating the pressure control mechanism.
 4. The method of claim 3wherein the pressure control mechanism includes a piston assembly, andchanging the pressure within the heat pipe includes applying acontrolled pressure using the piston assembly.
 5. The method of claim 4wherein the piston assembly is actuated by an electromagnetic actuator,and changing the pressure within the heat pipe includes applying acontrolled force to the piston assembly using the electromagneticactuator.
 6. The method of claim 4 wherein the piston assembly isactuated by an air bellows, and changing the pressure within the heatpipe includes applying a controlled force to the piston assembly usingthe air bellows.
 7. The method of claim 1 wherein measuring thetemperature associated with the heat pipe includes measuring thetemperature at the evaporator end.
 8. The method of claim 7 wherein thetemperature measured at the evaporator end is a boiling temperature ofthe fluid.
 9. A method for operating an exposure apparatus comprisingthe method for controlling the temperature of claim
 1. 10. A method formaking an object including at least a photolithography process, whereinthe photolithography process utilizes the method of operating anexposure apparatus of claim
 9. 11. A method for making a wafer utilizingthe method of operating an exposure apparatus of claim
 9. 12. A heatpipe comprising: an evaporator end; a fluid; and a pressure controlmechanism, wherein the pressure control mechanism is arranged to changea pressure within the heat pipe such that a boiling temperature of thefluid is changed.
 13. The heat pipe of claim 12 wherein the pressurecontrol mechanism is arranged to change the pressure by increasing thepressure such that the boiling temperature of the fluid is increased.14. The heat pipe of claim 12 wherein the pressure control mechanismincludes a piston arrangement, the piston arrangement being arranged toapply a control pressure to change the pressure within the heat pipe.15. The heat pipe of claim 14 wherein the pressure control mechanismfurther includes an actuator, the actuator being arranged to apply acontrol force to the piston arrangement such that the piston arrangementapplies the control pressure to change the pressure within the heatpipe.
 16. The heat pipe of claim 14 wherein the pressure controlmechanism further includes an air bellows, the air bellows beingarranged to cause the piston arrangement to apply the control pressureto change the pressure within the heat pipe.
 17. The heat pipe of claim14 further including: a temperature sensor, the temperature sensor beingarranged to measure the boiling temperature of the fluid.
 18. The heatpipe of claim 17 wherein the measured boiling temperature is provided tothe pressure control mechanism, the pressure control mechanism beingarranged to change the pressure by an amount determined using themeasured boiling temperature.
 19. The heat pipe of claim 17 wherein thetemperature sensor is arranged at the evaporator end.
 20. The heat pipeof claim 12 further including: a condenser end, wherein the pressurecontrol mechanism is positioned near the condenser end of the heat pipe.21. The heat pipe of claim 12 wherein the evaporator end is arranged tobe positioned near an external heat source.
 22. The heat pipe of claim21 wherein the external heat source is a coil of a linear motor within astage apparatus.
 23. An exposure apparatus comprising the stageapparatus of claim
 22. 24. A device manufactured with the exposureapparatus of claim
 23. 25. A wafer on which an image has been formed bythe exposure apparatus of claim
 23. 26. A method for controlling atemperature of an actuator within a stage apparatus, the stage apparatusbeing in communication with an evaporator end of a heat pipe, the methodcomprising: determining a desired temperature for the actuator; andadjusting a mechanism within the heat pipe to achieve the desiredtemperature for the actuator, wherein adjusting the mechanism causes aboiling temperature of a fluid within the heat pipe to be adjusted suchthat a temperature of the heat pipe is adjusted.
 27. The method of claim26 wherein adjusting the pressure within the heat pipe includes applyinga control force of a first amount to a piston arrangement of the heatpipe, wherein the control force of the first amount is arranged to causethe piston arrangement to change the pressure within the heat pipe. 28.The method of claim 27 further including: determining when thetemperature of the actuator is the desired temperature for the actuator,wherein when it is determined that the temperature of the actuator isthe desired temperature for the actuator, the control force ismaintained at the first amount.
 29. The method of claim 28 wherein whenit is determined that the temperature of the actuator is not the desiredtemperature for the actuator, adjusting the pressure within the heatpipe to achieve the desired temperature for the actuator furtherincludes applying a control force of a second amount to the pistonarrangement, wherein the control force of the second amount is arrangedto cause the piston arrangement to change the pressure within the heatpipe, the second amount being different from the first amount.
 30. Themethod of claim 26 further including: determining a correspondingdesired temperature for a section of the heat pipe using the desiredtemperature for the actuator, wherein adjusting the mechanism to achievethe desired temperature for the heat pipe includes adjusting themechanism to achieve the corresponding desired temperature for thesection of the heat pipe.
 31. The method of claim 30 wherein the sectionis the evaporator end.
 32. A method for operating an exposure apparatuscomprising the method for controlling the temperature of claim
 26. 33. Amethod for making an object including at least a photolithographyprocess, wherein the photolithography process utilizes the method ofoperating an exposure apparatus of claim
 32. 34. A method for making awafer utilizing the method of operating an exposure apparatus of claim32.
 35. A method for controlling a temperature of an actuator within astage apparatus, the stage apparatus being in communication with anevaporator end of a heat pipe, the heat pipe including a pistonarrangement, the method comprising: determining a desired temperaturefor the actuator; and adjusting the piston arrangement to achieve thedesired temperature for the actuator, wherein adjusting the pistonarrangement causes a boiling temperature of a fluid within the heat pipeto be changed such that a temperature of the actuator is changed. 36.The method of claim 35 wherein adjusting the piston arrangement includesadjusting an internal pressure of the heat pipe to change thetemperature of the actuator.
 37. The method of claim 35 whereinadjusting the piston arrangement includes adjusting an internal volumeof the heat pipe to change the temperature of the actuator.
 38. Themethod of claim 35 wherein adjusting the piston arrangement includesapplying a control force to the piston arrangement.
 39. The method ofclaim 38 wherein applying the control force to the piston arrangementcauses a control pressure to be applied using the piston arrangement,the control pressure being arranged to cause the boiling temperature ofthe fluid to be changed.
 40. The method of claim 35 further including:determining a corresponding desired temperature for a section of theheat pipe using the desired temperature for the actuator.
 41. The methodof claim 40 wherein the section is the evaporator end.
 42. A method foroperating an exposure apparatus comprising the method for controllingthe temperature of claim
 35. 43. A method for making an object includingat least a photolithography process, wherein the photolithographyprocess utilizes the method of operating an exposure apparatus of claim42.
 44. A method for making a wafer utilizing the method of operating anexposure apparatus of claim
 42. 45. A cooling device comprising: a heatpipe having an end portion that is arranged to be in vicinity of a heatsource; a fluid that is contained in the heat pipe; and a pressurecontrol mechanism connected to the heat pipe, the pressure controlmechanism being arranged to change a pressure within the heat pipe suchthat a boiling temperature of the fluid is changed.
 46. The coolingdevice of claim 45, wherein the heat pipe has an evaporator end and acondenser end, and the evaporator end is located on the end portion. 47.A heat transfer apparatus comprising: a flow passage; at least one heatreceiving section where heat is transferred from a heat source, the atleast one heat receiving section being disposed on the way of the flowpassage; a heat transfer medium filled within said flow passage, theheat transfer medium being circulated within the flow passage; and atemperature setting device connected to the flow passage, thetemperature setting device being arranged to change a state-shifttemperature of the heat transfer medium.
 48. The heat transfer apparatusof claim 47, wherein the temperature setting device changes a boilingtemperature of the heat transfer medium.
 49. The heat transfer apparatusof claim 47, wherein the temperature setting device changes a pressurewithin the flow passage.
 50. The heat transfer apparatus of claim 47,wherein the heat source is a part of an actuator within a stageapparatus.
 51. An exposure apparatus comprising the stage apparatus ofclaim
 50. 52. A method for controlling a temperature associated with aheat transfer apparatus, the method comprising: circulating a heattransfer medium within a flow passage, the flow passage including atleast one heat receiving section where heat is transferred from a heatsource; and changing a state-shift temperature of the heat transfermedium circulating within the flow passage.
 53. The method of claim 52,wherein changing a state-shift temperature includes changing a boilingtemperature of the heat transfer medium.
 54. The method of claim 52,wherein changing a state-shift temperature includes changing a pressurewithin the flow passage.
 55. A method for operating a stage devicecomprising the method for controlling the temperature of claim
 52. 56. Amethod for operating an exposure apparatus comprising the method forcontrolling the temperature of claim
 52. 57. A method for making anobject including at least a photolithography process, wherein thephotolithography process utilizes the method of operating an exposureapparatus of claim
 56. 58. A method for making a wafer utilizing themethod for operating an exposure apparatus of claim 56.